• 한국기계가공학회지
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• 제10권5호
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• pp.58-64
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• 2011

In this paper, research on the manufacturing technology of hexagonal structure core is investigated. Also the optimal forming process of the honeycomb core is developed and the rolling process is analyzed using finite element code, $DEFORM^{TM}$-3D. The standard honeycomb has a uniform hexagonal structure defined by the material, cell size, cell wall thickness and bulk density. Honeycomb core products can be made from any thin, flat material. The most common cell configuration is the hexagon but there are many other shapes for special applications. Because of the precision shape and the thin thickness, the honeycomb core is not easy to manufacture in the metal forming process. Through this study it was confirmed that after the rolling process, the section of honeycomb close to the standard shape can be obtained. This result is reflected to the manufacturing process design for the honeycomb core.

• 대한임베디드공학회논문지
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• 제5권2호
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• pp.77-83
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• 2010

In this paper, we propose an efficient memory architecture for coeff_token encoding in H.264/AVC standard. The VLCTs used to encode the coeff_token syntax element are implemented with the memory. In general, the size of memory must be reduced because it affects the cost and operation speed of the system. Based on the analysis for the codewords in VLCTs, new memory architecture is designed in this paper. The proposed memory architecture results in about 24% memory saving, compared to the conventional memory architecture.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1988년도 전기.전자공학 학술대회 논문집
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• pp.229-231
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• 1988

In this paper, we design adaptive DPCM by the two dimensional linear prediction using the covariance method and propose adaptive algorithm which determines analysis frame size by the compassion of the local standard deviation and the global standard deviation of images.

• Nuclear Engineering and Technology
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• 제54권1호
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• pp.401-413
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• 2022

This paper provides a simple method by which to estimate the cross-section stress profiles for nozzles designed according to ASME Code Section III. Further, this method validates the effectiveness of earlier work performed by the authors on standard nozzles. The method requires only the geometric information of the pressure vessel and the attached nozzle. A PWR direct vessel injection nozzle, a PWR outlet nozzle, a PWR inlet nozzle and a BWR recirculation outlet nozzle are selected based on their corresponding specific designs, e.g., a varying nozzle radius, a varying nozzle thickness and an outlet nozzle boss. A cross-section stress profile comparison shows that the estimates are in good agreement with the finite element analysis results. Differences in stress intensity factors calculated in accordance with ASME BPVC Section XI Appendix G are discussed. In addition, a change in the dimensions of an alternate nozzle design relative to the standard values is discussed, focusing on the stress concentration factors of the nozzle inside corner.

• ETRI Journal
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• 제31권5호
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• pp.489-499
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• 2009

This paper focuses on assessment and design of transmission systems for distribution of digital signals over standard Category-7A copper cables at speeds beyond 10 Gbps. The main contribution of this paper is on the technical feasibility and system design for data rates of 40 Gbps and 100 Gbps over copper. Based on capacity analysis and rate optimization algorithms, system parameters are obtained and the design implementation trade-offs are discussed. Our simulation results confirm that with the aid of a decision-feedback equalizer and powerful coding techniques, namely, TCM or LDPC code, 40 Gbps transmission is feasible over 50 m of CAT-7A copper cable. These results also indicate that 100 Gbps transmission can be achieved over 15 m cables.

• Steel and Composite Structures
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• 제5권4호
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• pp.327-343
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• 2005

The European Standards Organisation (CEN) has planned to develop a complete set of harmonized European building standards. The Eurocodes, being the design standards, form part of this total system of European standards, together with standards for fabrication and erection and product standards. After a period of experimental use of the ENV(European Pre Standard)-versions of the Eurocodes, these are now converted into official EN's (European Standards). Design of composite steel and concrete buildings and bridges is covered by Eurocode 4. An overview will be given of the historic development of Eurocode 4, the structure and contents of the EN version and the present status and planning for completion. The Eurocode treatment of some selected technical items will be presented in more detail.

• Structural Engineering and Mechanics
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• 제7권1호
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• pp.111-126
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• 1999

The work presented here focuses on the development of suitable discretised formulations, for large-displacement shape and non-shape design sensitivity analysis (DSA), which enable the straightforward incorporation of structural optimisation into established finite element analysis (FEA) codes. For the generalised displacement-based functional the design sensitivity vector has been expressed in terms of displacement sensitivity. The Total Lagrangian formulation is utilised for modelling of large deformation of truss structures. The variational formulation of the sensitivity analysis procedure is discretised by using "pseudo" - finite elements, Results are presented for the sensitivity analysis and optimisation of standard truss structures. For the purposes of this work, the analysis and optimisation procedures outlined below are incorporated into the FEA code ABAQUS.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 심포지엄 논문집 정보 및 제어부문
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• pp.270-272
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• 2006

In this paper, we discuss optimal design of Fuzzy Polynomial Neural Networks by means of Genetic Algorithms(GAs) using symbolic coding for non-linear data. One of the major subject of genetic algorithms is representation of chromosomes. The proposed model optimized by the means genetic algorithms which used symbolic code to represent chromosomes. The proposed gFPNN used a triangle and a Gaussian-like membership function in premise part of rules and design the consequent structure by constant and regression polynomial (linear, quadratic and modified quadratic) function between input and output variables. The performance of the proposed model is quantified through experimentation that exploits standard data already used in fuzzy modeling. These results reveal superiority of the proposed networks over the existing fuzzy and neural models.

• 한국CDE학회논문집
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• 제10권6호
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• pp.412-420
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• 2005

The integration of CAD and CAM is critical for computer aided process planning. Recently, STEP has been emerged and utilized as a product data exchange standard format in CAD/CAM areas. The assembly information consists of assembly component relations, assembly features, assembly directions and mating conditions. The purpose of this study is to develop an efficient algorithm to extract assembly information directly from the STEP based files and to generate automatically assembly process plan from the extracted assembly features. The developed algorithms will generate assembly information codes for STEP(AICS). The results from this study can be a reasonable link between design and manufacturing for developing better CAAPP(Computer-Aided Assembly Process Planning) systems.

• 한국재난정보학회 논문집
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• 제5권1호
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• pp.66-74
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• 2009

As building heights increase, so do these challenges in Korea. High-rise buildings present a variety of challenges to fire safety and protection. The fire protection technology in our country is still on a weak situation which is mainly due to the lack of concerns by the government, companies and citizen. This paper provides general guidance regarding fire-related property protection system for high-rise building performance based design. The importance of high-rise building in of the number of occupants, the value of property, and the a catastrophic loss would have on the community all warrant an increased level of protection and life safety. Because, We have to prepare a new spacial code and standard guidance for fire protection at the stage of the high-rise building design.